In many motor applications, positions of the motor are sensed. Once motor positions are sensed, power can be applied to operate these motors accordingly. Different applications have different motor phase sensing requirements. For example, the Timken Company's MPS160 can be used to determine an absolute position of a target magnet. However, chips such as the MPS160 typically can only be used to determine the absolute position of the target within each North (N)/South (S) pole pair only. These pole pairs can be up to 6 mm wide in some performance configurations. Furthermore, to cover ⅓, ¼, or ⅕ of a revolution, a very large single absolute position sensor chip may be required. A large single absolute position sensor can be difficult to apply in many applications, such as those that have a space limitation.
There are several application-specific-integrated-circuits (“ASIC's”) collectively referred to as motor sensors, that can be used to sense positions of a motor. For example, Timken's MPS32XF produces high resolution signals from a wide range of magnetic pole widths. This motor sensor is programmable and equipped with a Hall sensor array.
In some steering wheel applications, for example, in order to accurately control or activate a steering column, an absolute steering column position is needed over multiple turns of the steering wheel or column. To determine an absolute steering column position, some controllers will combine outputs of a turn counter with a position signal of a steering wheel over one revolution as provided by a sensing device. However, implementing a turn counter can be costly and can increase complexity of the sensing device.